M48 Ignition tuning help

[Cristian G]

Guys and girls,
I am a relative novice at the tuning game.
I help a mate look after his car. It's a BMW E30 M3 Group A car with the S14 B23 running in 1987 Group A trim. We have a M48 with wide band logging.
The inputs we have are the ones limited by the 1987 Group A set up. These are Ref, Sync, Speed, Fuel Px, Oil Px, Oil Temp, IAT, Manifold Air Px.
The engine still has the original configuration distributor fitted although we are running an upgraded Bosch ignition module to work with the M48.

My question is this:
How do I know when I have dialled into much ignition advance?

The original set up was done on a dyno, and for the past few races I have been fine tuning the fuel mapping. I think I have pretty much hit the limit on fuel tuning, but think I can get more power from fine tuning the ignition map.

I understand the principle of "pinging" and detonation, but if I advance the ignition say 0.5-1deg and it's too much is there anyway to tell, apart from the drivers "butt dyno"?
Also is there a way to prove that the advance has helped if the driver fails to "pick up" the increase in performance?

Thanks for your time and help with this.

Regards

Cristian

[RossB]

Hello Christian,

The only way to do this safely is on a dyno with some means of detecting knock someone experienced with tuning. This is also the only way to prove if the changes made are making a difference. A driver would not be able to tell unless the change was substantial and the driver will not be able to hear an engine knocking at higher RPM as there will be too much noise from other parts of the car. Fine tuning the fuelling on the track is fine but I would not recommend this for ignition tuning.

[Cristian G]

Thanks Ross.

I thought that might be the case, especially as we don't have knock sensors and cannot fit them.

I thought I would ask though as there is a huge amount of info available and in peoples experience and I am only learning.

Have a good day.

Cristian